The invention relates to a conveying and processing system for resin bottles, and in particular, to a conveying and processing system for resin bottles which allows the bottles to be filled and capped while their necks are held for purpose of conveyance.
A conveying and processing system for resin bottles has been extensively used in the art in which bottles formed of a resin are sequentially handed to a rotary bottle processor such as a filler, a capper or the like to perform a liquid filling or a capping thereof. An intermediate wheel is arranged in such a conveying and processing system between successive rotary bottle processors to hand the resin bottles from processor to processor.
The intermediate wheel which hands over bottles between a rotary filler and capper is provided, an arrangement is also known in the art in which a plurality of pairs of arms which can be opened and closed in each pair are disposed at an equal circumferential spacing around the outer periphery of a revolving body so as to be each capable of gripping the barrel of a bottle to convey and hand it as the revolving body rotates, thus serving as bottle feeder means to feed bottles to a bottle processor such as a filler.
In the described arrangement in which the barrel of the resin bottle is gripped by the pair of arms as the latter open and close for purpose of conveyance, there arises a problem that as the bottle changes in size or configuration, positions where the bottle is gripped and where it is released also change to require an exchange or other adjustment of its attachment. To cope with this problem, there is proposed a conveyor system with an improved flexibility for a combined use in which a neck of a bottle, which experiences a less variation in diameter as compared with the barrel of the bottle, is gripped (Japanese Laid-Open Patent Application No. 129, 921/1992).
When conveying the bottle while holding its neck, if the bottle is allowed to slide on a fixed plate, a friction produced by the bottom surface of the bottle may cause a tilting or an unstable attitude of the bottle. Accordingly, the conveyor system disclosed in the cited reference conveys the bottle in a suspended manner while gripping the bottle neck.
Nevertheless, conveying by rotation the resin bottle while gripping its neck and holding it in a suspended manner causes the bottle bottom to be swung outward under the influence of the centrifugal force, causing a problem of instability in the attitude in which the bottle is conveyed. In particular, when conveying the bottle after it has been filled with liquid by the filler, the increased weight of the bottle increases the influence of the centrifugal force to add to the instability of conveyance, which in turn results in the instability of hand-over operation. A practice in the art which prevents the bottle bottom from being swung outward when it is introduced into a capper has been to provide a guide member toward the outer periphery of the intermediate wheel where the bottle bottom is likely to be situated for abutment against it.
However, this approach suffers from the requirement that the guide member must be replaced whenever the bottle changes it external diameter or height. In addition, because the bottle bottom is constructed soft and exhibits a reduced strength, there is a likelihood that the bottle may be deformed when it abuts against the guide member.